Chuck Banshee found:
this interesting paper from the Journal of Agricultural and Food
Chemistry, 2007, 55, pages 8657-8663 titled:
Use of Human Urine Fertilizer in Cultivation of Cabbage
(Brassica oleracea)––Impacts on Chemical, Microbial, and Flavor Quality
http://www.nku.edu/~longa/classes/ca...esources/docs/
cabbage.pdf

my question is HOW best to keep the nitrogen in the compost from
turning into ammonia gases and simply venting away.

I have to ask why ? As an academic exercise? Not much reason to save
it. Urine is pretty cheap and fairly renewable for most of us. In a
compost pile I would let it go do it's job unhindered. Unless you test/
analyze your homebrew, hot or cold, your only guessing as to its
nutrient content. So the urine is just feedstock and not a nutrient
at this stage.

As for using urine in your soil, you and others gave some good info as
to how best to use. I did read excerpts from one of the Finnish
team's three experiments wherein “Surendra K. Pradhan, K. Holopainen
and Helvi Heinonen-Tanski of the University of Kuopio in Finland
collected human urine during the winter of 2007-2008 from several eco-
toilets in private homes. The urine was stored for about six months at
45 degrees F and tested for microbes and bacteria. The team mixed it
with wood ash collected from a household furnace, and found the
mixture was just as good as -- or better than -- conventional chemical
fertilizer.” So I would assume urine was relatively shelf stable for
at least that amount of time/temp. Here is a lead on her email if you
want to ask first hand: .

WA State's land grant site on Composting :
http://whatcom.wsu.edu/ag/compost/fu...tals/index.htm

Another link that maybe helpful w/ your quest:
http://ciitn.missouri.edu/cgi-bin/pu...3&c_id=2007009

I do have to say that while the average person's urine maybe safe
there is increasing concern about Environmental Pharmaceutical
Persistent Pollutant (EPPP) which do show up in edible plant, albeit
in low doses. Always test or know your source well!

good luck